Carriage Bolts

We offer a wide range of metal bolts and studs. What is the difference between screws and bolts?

Bolts can be described as long shafts with a distinct head on one side. These are generally partially threaded.

A fully threaded bolt is referred to as a screw.


Square Neck Carriage Bolts

This is known by different names such as Carriage Bolts, Coach bolts/ Round Head Square neck bolt, Mushroom Head Square neck bolt etc. Useful for fastening wood and metal together.

It is distinguished from other bolts by its shallow mushroom head followed by a square neck, while the shank cross section of the bolt is circular.


This gives the bolt its self locking feature. The square neck grips into the part being fixed preventing the head from turning when the nut is tightened.

Standard – DIN 603. Mild Steel and Stainless Steel

SS-304 A2

SS-316 A4

Standard – ASME-B18.5.

SS-304 A2


Installation Notes

Use a correct size drill bit which should be the same as body diameter of the bolt.

Drill a hole using a slightly slower speed to obtain a correct round hole.


Next slide the bolt into the hole (you may need a hammer as the hole should be just big enough for the bolt to go through).


Place the washer on the rear side of the bolt followed by the nut. The washer will help to distribute the force you are about to put onto the nut to pull the bolt into the wood. This will not only protect the wood on the back side but also keep the bolt from digging into it and getting stuck.


Tighten the nut. The square shoulder on the bolt will be pulled into the wood. Once the underside of the head rests against the wood, the carriage bolt is officially installed.